1. Field of the Invention
The present invention relates generally to tampon pledgets and their relationship to tampon applicators. More particularly, the present invention relates to an improved method for post forming a rounded insertion end of a tampon pledget in an open-ended tampon applicator. The tampon pledget forms a cushion at an open tampon insertion edge of the tampon applicator and yet it is held securely in the applicator in order to be ready for use.
It is known that a rounded insertion end of a tampon assembly, which includes a tampon pledget and a tampon applicator, aids in the insertion of the pledget into a vagina. There are two known methods for forming a rounded insertion end for a tampon assembly. The first is to form rounded, flexible petals at the insertion end of the applicator to cover the blunt insertion end of the pledget. The second is to form a rounded insertion or forward end of the pledget which would be used with an open end of the applicator.
Concerning the latter, a great amount of axial force at the forward end of the pledget is needed to achieve a rounded shape. Also, an opposing force to support the pledget against the axial force is also necessary. In particular, the axial force may exceed the columnar strength of the pledget and, thus, a substantial amount of radial support for maintaining the column integrity of the pledget is required during formation of the rounded forward end of the pledget. Due to the difficulty of providing adequate radial support, existing methods preform the rounded shape at the forward end of the pledget before the pledget is inserted into the applicator. In this manner, the outer cylindrical wall of the pledget can be supported easily and directly since the pledget has not yet been positioned within an applicator. Such a preformed pledget must be carefully inserted, string end first, through the open end of the applicator after forming the rounded forward end in order to preserve the preformed forward end and to provide an adequate fit for holding the pledget. Accordingly, an expensive and complicated process for assembling the tampon assembly has, heretofore, been required.
2. Description of the Prior Art
It has been recognized in the industry that a pledget having a preformed insertion end is desirable. For example, U.S. Pat. No. 3,345,255 to J. Hochstrasser, et al. titled APPARATUS FOR TREATING ELONGATED DEFORMABLE ARTICLES, provides a spiked rotating tool for forming a central depression or recess within the forward end of a tampon pledget. The depression increases the rate of absorption of menstrual fluids at the forward end of the pledget. Similarly, U.S. Pat. No. 3,515,138 to Hochstrasser, et al. titled PROCESS AND APPARATUS FOR TREATING ELONGATED DEFORMABLE ARTICLES is a division of the application that matured into the above-discussed U.S. Pat. No. 3,343,225, and is directed particularly to the above-described pledget.
The above patents provide a method for preforming a central depression in a pledget to increase its absorbency capability, regardless of the material with which it is made. However, they do not provide a method for post forming the depression after the pledget has been inserted in an applicator.
There is a need for a method of producing tampon products by forming the rounded insertion end or forward end of a pledget subsequent to insertion in the applicator. For such a method, the number of steps required to assemble and manufacture the tampon product would be reduced and, accordingly, the time and cost to assemble and manufacture the tampon product would be reduced as well.
In addition, the above patents do not provide a method for shaping the forward end of a pledger over the open end of an applicator in order to form a rounded insertion end for the tampon assembly. In fact, the above patents particularly provide that the insertion end of the pledget be confined and encompassed within applicator. This is presumably to minimize the propensity of the applicator to engage the forward end of the pledget during ejection and, thus, loosen its fibers.
Still further, the above patents do not provide the quicker, simpler and less complex method of the present invention.